Our goals are to design, build and demonstrate, in the field, a radically new passive microwave radiometer, primarily intended as an atmospheric sounder. By taking advantage of new developments in miniaturization we intend to build an instrument which, in terms of mass and power, is an order of magnitude smaller than the current state of the art but with equal functionality and performance. Moreover, we plan to implement a flexible and modular design, so that the basic instrument design can be easily reconfigured to meet specific mission needs. We also expect the eventual cost of this instrument to be significantly lower than that of equivalent state-of-the-art systems. Thus, we aim to develop a small, low cost observational resource capable of application to multiple missions on observational platforms which were previously not feasible. This will open up new measurement regimes and opportunities to make important supplementary atmospheric and surface observations which will be invaluable for investigations of climate and related research areas.

The new technology and many of the proposed design concepts build on prior design and development work carried out at the Jet Propulsion Laboratory under NASA's sponsorship. The proposers have played significant roles in those efforts and have many years of experience in microwave science, instrument design and technology development.

During the first year we propose to build a dual-band tropospheric temperature sounder, operating at 50-60 GHz and at 118 GHz, implemented with MMIC technology. We will then operate this instrument on a high altitude remotely piloted aircraft or similar platform and validate the measurement concepts and the new technology. In the second year we will reconfigure the instrument to also incorporate water vapor sounding at 183 GHz and operate this configuration on a similar aircraft platform.